Grazing behaviour,intake and performance of dairy ewes with restricted access time to berseem clover (Trifolium alexandrinum L.) pasture |
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| Authors: | G. Molle M. Decandia V. Giovanetti C. Manca M. Acciaro G. Epifani L. Salis A. Cabiddu M. Sitzia A. Cannas |
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| Affiliation: | 1. Dipartimento per la Ricerca nelle Produzioni Animali, Agris Sardegna, Olmedo, Italy;2. Dipartimento di Agraria, Università di Sassari, Sassari, Italy |
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| Abstract: | The effects of restricted access time to pasture (2, 4 or 6 h d?1; 2H, 4H or 6H) on ingestive behaviour and performance were assessed on four occasions per target grazing day (D1, initial day; D4, intermediate day; and D7, final day) in dairy ewes rotationally grazing berseem clover with a 7‐day grazing period and a 21‐day recovery period. A randomized block design with two replicates per treatment was used. All ewes were supplemented daily with 700 g per head of concentrates and 700 g per head of ryegrass‐based hay. Pasture subplot and animal group data were analysed by a factorial model including access time (AT), grazing day (D) and their interaction as fixed factors. Sward height decreased from D1 (P < 0·001) and green leaf mass from D4 (P < 0·001) onwards during the grazing period. Grazing time as a proportion of AT was higher in 2H than in 4H and 6H ewes on D1 and D4 but not on D7 (P < 0·05 for AT × D). Herbage intake rate was higher in 2H than in 4H and 6H ewes (P < 0·001). Herbage and total intakes were higher in 4H and 6H than in 2H ewes (P < 0·001), with herbage intake varying non‐linearly during the grazing period (P < 0·05). Milk yield was higher in 4H and 6H than in 2H ewes (P < 0·01). To conclude, despite the evidence of compensatory behaviour, restricting access time to 2 h d?1 constrained intake and performance of dairy ewes rotationally grazing berseem clover. |
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| Keywords: | sheep milk nutrition
LAI
Legumes rotational grazing |
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